Outdoor temperature responsive controller for heating systems



June 19, 195] JUDSQN 2,557,661

OUTDOOR TEMPERATURE RESPONSIVE CONTROLLER F OR HEATING SYSTEMS Flled Oct 8 1945 [Wavroe 1. J00: o/v

Patented June 19, 1951 OUTDOOR TEMPERATURE RESPONSIV E CONTROLLER FOR HEATING SYSTEMS Albert L. Judson, Portland, Oregz, assignor to Iron Fireman Manufacturing Company, Bortland,

Oreg.

Application October 8, 1945, Serial No. 621,143

8 Claims.

' This invention relates generally to controls for heat generating devices and particularly to an outdoor controller.

The main object of this invention is to provide an outdoor controller whereby a heating system is run at intervals, varied by the outside temperature.

I accomplish these and other objects in a manner set forth in the following specification as illustrated in the accompanying drawing, which is a perspective view showing in partial perspective and partial diagram the general arrangement of the device.

Similar numerals refer to similar parts throughout the several viewsl Referring in detail to the drawing there is shownvby way of illustration, a shaft Ill mounted on suitable bearings (not shown), and having secured thereon a ratchet wheel II, whose teeth I-2' engage the pawl I3 whose arm I4 is eccentrically mounted on the crank I5 on the shaft I6 of a motor IT. The outer end of pawl arm I4 is supported on inclined resilient blade I8, so that as pawl arm I4 is advanced by movement of crank I5. pawl I3 engages teeth I2 and as pawl arm I4 is retracted pawl I3 moves clear of teeth I2. Stationary pin 8| contacting-the upper inclined surface 82 of pawl arm I I-assures the complete retraction of pawl I3 from teeth I2 of gear II at every revolution of shaft I6 of timin motor IT. A trip pin |9 lis mounted on the side of the ratchet wheel I I. Also engaging the teeth I2 is apoint 20 of a retaining pawl 2 I, which is pivoted on the pin 22. The pawl 2| has an arm 23 which is oil'set from the point 20 and extends alongside of the gear I I in the path of the trip pin I9 so that as the pin I9 travels about in its orbit and engages the arm 23, it will release the point 2I'Iv and permit the gear II to. return to its zero position against the straight side 24 of the arm 23 A light spring 25 urges the point '20 away from the teeth I2.

On the upper side of the .pawl 2| is formed a projection 26 whichmayengage the compensating thermostatic element 21, which is in the form of a bimetal blade secured on the rock shaft 28. To shaft28 is alsorsecured an operating .thermostaticelement 29, which is, adapted to ride upon the cam 3.0 secured onthe shaft Ill. The operating thermostatic element 29 is provided with a heating-element 3 I, the, parts being so constructed that the free end of the member 29 rises upon cooling; that is, it curls upwardly while it curls downwardly upon heating. On the shaft I0 is mounted a switch lever 32., which is urged in a direction opposite to: the one inlwhich the gear H isdriven by means of a coiled spring 33, which is anchored on the pin 34 and engages the lever 32. The lever 32 has an extending point 35 adapted to engage the leaf 36 of a switch whose member 31 is stationary.

Secured to the shaft 28 is an arm 38, to which is attached a spring 39 adapted to urge the mem ber'29 toward'the cam 30 and the member 2'! toward the projection 26. In the form of the device shown, the mechanism above described is located inside of the wall 4|] orabove the floor 4|.

As continuously running motor shaft I6 rotates cam or crank I5 the pawl I3 on arm I I'is vertically located between spring member I8 and fixed pin 8| to alternately advance ratchet wheel II in a clockwise direction and then to retract clear-of ratchet teeth I2. Normally when pawl I3 clears-teeth I2, wheel II will be'prevented from counterclockwise rotation due to the action of spring 33 by detent pawl 2| whose point 20 is forced to ride the periphery of wheel II by the downward pressure of member 21 on lobe 26 of pawl 2|. However tension spring 25 constantly biases pawl 2| towards counterclockwise rotation aboutpin22 and should the pressure of member 2.! on lobe 26 ease to a designed value spring 25 will lift pawl 20 out of engagement with teeth I2 as pawl I3 advances wheel II and thereby eases the pressure of teeth I2 on pawl point 20. Pawl 2| then rotates under the urge of spring25 in a counterclockwise direction until member 21 comes to rest on the diagonal flat to the right of lobe or projection 23. The same action of releasing wheel II for counterclockwise rotation would occur after wheel II has been advanced step by step by pawl I3 until pin I9 had struck the left hand face of arm 23 of pawl 2 I. When, by either means, wheel II is released for counterclockwise rotation due to spring 33, and the counterclockwise rotation of wheel II and shaft I0 proceeds untilstoppedby pin I9 on wheel I I contacting the face 24 of leg 23 of pawl 2| causing pawl 2| to rotate clockwise about pin 22 to its reset position with point 23 engaging teeth I2 of wheel II. However'before wheel II has finished its counterclockwise rotation with pin I9 stopped against face 24. of pawl 2| point 35 of switch operating lever 32: has engaged resilient switch blade 36 and pressed blade 36 into contact with switch blade 3.1 both of which blades are flexible enough to allow pin I9 to complete its resetting duty on pawl1-2I. vSwitch blade 36 is normally biased away from blade 31 and as pawl I3 starts again to r0- tate wheel |1I step by step in a clockwise directionllever '32. moves away from blade 36 and '3 wlnch due to its bias then loses its contact with blade 31.

There is also provided a pilot thermostat 42 which is preferably out of doors, where it is subject to prevailing weather conditions. The thermostat 42 carries within itself a pilot thermostatic element 43, which by way of example, is adjusted to break contact at 65 degrees F. but will close at any temperature below 65 degrees F.; that is, at a temperature below 65 degrees F. the element 43 will contact the point 44 and close the circuit through the pilot heater 45, through which current flows to the heating element 3|, which is wound on the strip 46. The leads 4! and 48 which connect the heating element 3| to the pilot heater 45 and the pilot thermostatic element 43 are preferably connected by a proportioning resistor 49 to provide better control for the relative heating actions of the elements 45 and 3|. The purpose of the element 21 is merely to provide a balance or to compensate for the ambient temperature effeet on the control element.

Power is supplied to the thermostat circuit by connecting into line 41 the secondary coil of a transformer which receives its energy from the power line which also supplies energy to motor A feature of this device is the employment of a pilot thermostat which controls two series heaters, one a pilot heater 45 which affects the pilot thermostatic element and the other an operatingheater3| which affects the operating thermostatic element 29 in proportion to the heat required to maintain the pilot at its control position.

When applied to an outdoor controller, as illustrated herein, the pilot thermostatic element 43, together with its pilot heater 45 is placed outdoors and is adjustable (with no current on the heater), to break contact first as the temperature rises past 65 degrees F. and of course to close when the temperature passes 65 degrees F. in the opposite direction. When connected as illustrated, any temperature below 65 degrees F. will cause the pilot thermostatic element 43 to close the circuit through the heaters 45 and 3|, and it will remain closed until sufficient heat has been dissipated in the pilot heater to cause the pilot thermostatic element to open the circuit again.

It is obvious that the level of heat dissipation in the pilot heater will be substantially inversely proportional to the outdoor temperature. The operating element heater 3|, being connected in series, will also dissipate heat at a level proportionateto the heat level of the pilot heater. In this device, the operating heater 3| is arranged to heat an operating thermostatic element 29, and

is variably positioned by the effects of said heater. With such an arrangement, the thermostatic element is governed by the temperature surrounding the pilot thermostatic unit.

The operation of the essential part of my invention is as follows:

The operating thermostatic element 29 is engaged by a cam 3|! driven by a timing motor [1 through a ratchet mechanism II and I3. The element 29 is mounted on a hinge member or shaft 28, which also carries a thermostatic element 21 which compensates for the ambient temperature effect upon the control element.

This compensating element is arranged to hold the-retaining pawl into engagement with the ratchet wheel and opposes a spring 25 (or weight) which tends to disengage the pawl. The entire hinge member assembly is spring loaded by means of a spring 39 in such a manner as to urge the thermostatic elements to contact the cam 30 and pawl 2| respectively. As stated, it is the object of this device to run the heating system at intervals varied by the outside temperature.

Referring particularly to the diagram, when the ratchet wheel H is rotated by the driving pawl |3 on the timing motor l1, it carries with it the cam 30 and the switch lever 32. As the cam 30 progresses it will eventually lift the operating thermostatic element, which will in turn lift the compensating element away from the projection 26 allowing the point 20 to disengage the ratchet wheel under the urging of the spring '25. The entire cam shaft assembly will then be returned to the starting position by the spring 33. A pin IS on the ratchet wheel II is so arranged as to reengage the retaining pawl 20 with the ratchet wheel teeth |2 when the starting point is reached.

When the pawl l3, which is continually moving under the action of the crank I5, reengages the ratchet wheel I the ratchet shaft assembly starts to advance again. This cycling continues as long as the control element is within the control range and the length of each cycle being determined by the position of the control element. The proportioning resistor 49 provides a means for adjusting the proportional heating relation between the heaters 3| and 45.

It will be noted that the running of the heating plant is initiated by a switch whose points 38 and 31 are held closed by the switch lever 32 only when the cam shaft assembly is at the starting or rest position. Switch 36, 31 is therefore a momentary contact switch which is to be understood as connected in parallel with the holding circuit of the relay commonly used to control the operation of the heat supply means of a heating system. Subject to another condition influenced by the operation of the heating plant, another switch in the holding circuit is commonly used to stop the supply of heat initiated by the closure of switch 36, 31. Since the heating plant control circuit is not the unique part of my invention it is not here illustrated.

While I have thus illustrated and described my invention, it is not my desire to be limited to the precise form shown herein, and I intend to cover such forms and modifications of the invention as fall fairly within the appended claims.

I claim:

1. A control of the class described consisting of a rock shaft, a pair of bimetallic thermostatic elements secured to said rock shaft, one of said elements constituting a compensating thermostatic element and the other an operating thermostatic element, a shaft actuating said rock shaft having a switch lever mounted thereon, a switch disposed in the path of said lever, a spring on said shaft for rotating same in a manner to bring said switch lever into engagement with said switch in a manner to close same, a ratchet wheel on said shaft, a timing motor for actuating said ratchet wheel, a retaining pawl engaging the teeth of said ratchet wheel and urged into engagement therewith by said compensating thermostatic element, said retaining pawl having a spring thereon urging same away from the teeth on said ratchet wheel, an arm on said retaining pawl extending along the side of said ratchet wheel, said ratchet wheel having a pin extending from the side thereof adapted to engage said arm when the starting point is reached and thereby move the retaining pawl into engagement with the teeth of the -ratehet wheel, a cam on said shaft intermittently engaging said operating thermostatic element for the purpose of-actuating said rock shaft, and meansresponsive to outdoor temperatures co-operatingwith the operating thermostatic element to'vary the angular position-on said cam at which said cam engages saictoperating thermostatic element.

operating mechanism fona momentary contact switch, said mechanism comprising: :a shaft, time-controlled means for. rotating said shaft in one direction from"'an initial position, means constantly urging theishaft in the opposite direction back to saidiinitial position, means carried by said shaft for closing said switch when the shaft is in said initial position, a rock shaft, a thermostatic element carried by the rock shaft, a cam on the shaft engaging said element to rock the rock shaft upon a chosen angular movement of the shaft, means urging the rock shaft to hold the element against the cam, heating means controlled by the outside temperature for moving the element to rock the rock shaft in the same direction as the rock shaft would be moved by the cam after said angular movement, a ratchet gear fixed to said shaft, a retaining pawl engageable with said gear for preventing movement of the shaft to initial or switch closing position, means constantly urging the pawl into inoperative position, and resilient means carried by the rock shaft and engaging said pawl for overcoming the last mentioned means and therefore preventing reverse movement of the shaft until the rock shaft is rocked.

3. The device of claim 2 in which the resilient means carried by the rock shaft is a compensating thermostatic element. 7

4. The device of claim 2 in which the ratchet wheel carries a trip pin, and said pin on reverse movement of the shaft engages the retaining pawl to move the pawl against the urge of the means urging the pawl into inoperative position, whereby to restore the pawl to retaining position.

5. The device of claim 2 in which the heating means includes a thermostat, an electric heater proximate the thermostat, a second electric heater proximate the element carried by the rock shaft and engaging the cam, and a circuit including the two heaters and a contact engaged by the thermostat when the outdoor temperature falls below a chosen degree, such as 65 R, whereby the time periods between returns of the shaft to initial position will be varied in accordance with the time of dissipation of heat from the heater proximate the outdoor thermostat.

6. An operating mechanism for a momentary contact electric switch, said operating mechanism comprising a switch closing means having an initial position, defined as its position when said switch is closed means biasing said switch closing means to its initial position, a continuously running constant speed motor, means for adapting said motor progressively to move said switch closing means away from its initial position, a detent means for maintaining said switch closing means away from its initial position, means for opening said switch as said switch closing means moves away from its initial position, delay means for releasing said detent means in response to a variable condition whereby said biasing means may become effective to return said switch closing means to its initial position, and means operable by said switch closing means as said switch closing means returns to its initial position to reset said detent means, said delay means comprising means iresponsive "to a variable condition for vary ng 'the 'duration of said delay, said variable condition --responsive means "comprising a first thermally responsive element near said switch, a second thermally responsive element near said switch' a nd -responsive to the ambient temperature at itsl'ooation, means-for supplying heat "to said-first thermally responsive element in proportion to thevariationof a remote condition, andmeanscouplin'g 'said first and second elements to compensate said variable condition responsive means for ambient temperature.

'"7. JAnoperatingJmecl-Ianism for a momentary contact electric switch, said operating mechanism comprising a switch closing means having an initial position, defined as its position when said switch is closed means biasing said switch closing means to its initial position, a continuously running constant speed motor, means for adapting said motor progressively to move said switch closing means away from its initial position, a detent means for maintaining said switch closing means away from its initial position, means for opening said switch as said switch closing means moves away from its initial position, delay means for releasing said detent means in response to a variable condition whereby said biasing means may become effective to return said switch closing means to its initial position, and means operable by said switch closing means as said switch closing means returns to its initial position to reset said detent means, said delay means comprising means responsive to a variable condition at a remote location for varying the duration of said delay, said variable condition responsive means comprising a first thermally responsive means near said switch, a second thermally responsive means near said switch and coupled to said first thermally responsive means for ambient temperature compensation, and electric circuit means for supplying heat to said first thermally responsive means.

8. A momentary contact electric switch normally biased to open position, in combination with a condition responsive operating mechanism for aperiodically closing said switch, said mechanism comprising a continuously running constant speed motor, an operating shaft, an operating lever secured to said shaft and positioned to close said switch at a predetermined position of said shaft, a cam faced member secured to said shaft, a ratchet wheel secured to said shaft, spring means biasing said operating shaft to the switch closed position of said operating lever, a pin secured to said ratchet wheel, a rock shaft, a bimetal element secured at one end to said rock shaft and having its other end in position to contact said cam face depending on the angular positions of said operating shaft and said rock shaft and the warp of said bi-metal, a V shaped member pivoted at the base of the V, one leg of said V shaped member forming a holding pawl positionable to engage said ratchet wheel, the other leg of said V shaped member positioned in the orbit of said pin, spring means biasing said holding pawl away from said ratchet wheel, a detent arm fixed at one end to said rock shaft and having its other end positioned to contact said V shaped member to oppose said holding pawl biasing means with a force varying in accordance with the position of said rock shaft, spring means biasing said rock shaft towards a position of greater pressure of said bi-metal on said cam face and of said detent arm on said V shaped member, a driving pawl having one end eccentrlcally journalled on said motor shaft and having its other end guided'to alternately engage and disengage with said ratchet wheel, a first electric heater associated with said bi-metal member, a thermostat at a remote location, a second electric heater associated with said thermostat, a source of power, and circuit means connecting said electric heater, said thermostat and said soure of power in series.

ALBERT L. JUDSON.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 8v 1 UNITED STATES PATENTS Name Date Merrill July 26, 1932 Taylor Sept. 5, 1933 Webb Oct. 3, 1933 Shivers June 5, 1934 Cram June 24, 1941 Denison et a1 Aug. 5, 1941 Baak et al Aug. 12, 1941 Spangenberg Aug. 4, 1942 FOREIGN PATENTS Country Date France May 31, 1941 

